Sugar cane mill



E. A. SCHWARZ {:1- AL 2,205,632

SUGAR CANE MILL FilQd D50. 5, 1936 2 Sheets-SheeL1 June 25, 1940.

Gwen/ions EUGENE. A.5CHWARZ M OTTO FAaER June 25, 1940. a SCHWARZ H M2,205,632

SUGAR CANE HILL Filed Dec. 5, 1936 2 Shets-Sheet 2 Patented June 25,1940 UNITED STATES SUGAR CANE MILL Eugene A. Schwarz, Snyder, and OttoFaber, Kenmore, N. Y., assignors to George L. Squier ManufacturingCompany, Buffalo, N. Y., a corporation of New York Application December5, 1936, Serial No. 114,35

4 Claims.

Our invention relates in general to sugar cane mills and in particularto hydraulic accumulators and emergency controls'for such mills.

It is well known to those skilled in the'art that hydraulic accumulatorsformerly used on this class of machinery were actuated by weights placedon top of the accumulator, the pressure being governed by weights on theaccumulator piston. The disadvantage of such a system, when weights areused, is that the inertia of the weight, when set in motion, must betaken into account when designing the apparatus, with the result thateither the working weight is insufiicient, under normal working ccnditions, or there will be an excess pressure exerted upon the pistondue to the inertia of the weight when it is set in motion, therebycausing momentary overloading.

The principal object of our invention has been to provide a device ofthis nature having an accumulator, preferably of a differential type.whereby the pressure exerted upon the pistons of the mill bearing blockswill be taken by a separate piston which is subjected to substantiallyconstant air pressure.

Another object hasbeen to provide a device of such a nature that thereshall be substantially no inertia to overcome when the parts are firstplaced in motion.

Another object has been to provide a device so designed that a number ofmills may be controlled by a single conveniently located valve, whereby,in an emergency, the pressure upon all of the mills will be relieved.

Another object has been to provide sufficient reserve air so that abattery of accumulators may operate for fairly long periods of timewithout requiring the use of power to replenish air used therein.

Moreover, our device is so designed that the pressureexerted between therolls may be more accurately indicated than is possible in present daydevices.

Furthermore, our device is of such a nature that the air accumulator ofeach mill occupies a relatively small space and may be convenientlyarranged in any desired position.

Moreover, our device is relatively inexpensive to manufacture and issimple in design so that it may be operated over long periods of timewithout adjustment or alteration.

The above objects and advantages have been accomplished by the deviceshown in the accompanying drawings, of which:

Fig. 1 is a side elevation, partly in section, of a single unit of ourdevice.

Fig. 2 is a fragmentary, plan view showing portions thereof.

Fig. 3 is an enlarged, sectional view of the accumulator of one of theunits of our device.

Fig. 4 is an enlarged; fragmentary. sectional view of the pressurerelief device forming a part of our invention.

Fig. 5 is a similar view of an air relief valve forming a part ofourinvention.

Fig. 6 is an enlarged, fragmentary, sectional view of one of the bearingblock cylinders of our device.

Fig. 7 is an enlarged, plan view of one of the housing yokes with thecylinder cap removed.

Fig. 8 is a diagram, illustrating a battery of mills controlled by ouraccumulator system.

In the drawings we have shown but one unit of our device comprising asugar cane mill l0 and an accumulator ll supplied with air from an airstorage tank l2 and controlled by a single release valve l3, but it-isobvious that the air storage tank and the emergency release valve can beused to control the usual or desired number of mills and accumulators.

Each of the mills comprises the usual rolls l5 and I6 mounted-insuitable bearing standards I! and driven by suitable gears l8. As iscustomary in mills of this type, the upper bearing blocks 20 areslidably mounted in suitable guides 2| at the upper end of whichisstationarily arranged a housing yoke 22 or its equivalent, having ahousing cylinder 23. In each of these cylinders is disposed a housingpiston 24. Each of these pistons is provided with a downwardly extendingpiston rod 25 which passes through a suitable aperture 26 and has itslower end engaged with and bearing upon a plate 21 which rests on top'of the bearing block 20. Arranged in the upper end of the cylinder is aspacer disc 28 which is disposed in an enlarged bore 29 and held withinsuch bore by means of a cylinder cap 30. 'll'his cylinder cap isdesigned to keep the spacer disc 28 in place and it is securedpreferably to the housing yoke by means of a bayonet joint, lugs 3|formed on the cap being engageable with yoke recesses 32 when the cap isbeing assembled and engageable with yoke lugs 33 when the cap is 'inassembled position (see Figs. 6 and 7). Within the cylinder are twopacking rings 34 and 35, the former bearing against thev spacer disc 28and the latter being preferably secured to the top face of the housingpiston 24, so that the joints at these points will be sealed. V Eachof'the housing cylinders 23 is provided with an inlet opening 36 towhich is secured a fluid to be hereinafter described.

In carrying out our invention, one of the accumulators H shown in thedrawings is provided for each of the mills used. Each of theseaccumulators preferably comprises an outer jacket 3! closed at thebottom by a head 46 which may also serve as a base for the accumulator.Each of the accumulators is preferably arranged vertically and may besupported upon the floor or upon a side wall, or be suspended from theceiling. Within the jacket 39 is arranged an air cylinder 4| whichextends into the jacket for only a portion of the length thereof, andthis cylinder may be supported in any suitable and convenient way. Forconvenience of illustration, we have shown the cylinder as provided witha flange 42 which is supported upon a flange 43 carried at the top ofthe jacket. This air cylinder is preferably smaller than the jacket andis in interspaced relation therewith so as to give to the jacket avolumetric capacity such that there is very little rise in pressure inthe jacket under the normal working range of the device. Slidablymounted within the air cylinder is an air piston 44 which is providedwith suitable packing. In the lower end of the jacket 39, below thelower end of the cylinder 4|, is preferably arranged a number of guides61, so that if the piston 44 leaves the cylinder in its downward traveldue to lowering of air pressure in the jacket or for other reasons, thepiston will be guided within the jacket and kept in alignment with thecylinder so that it may be easily replaced within the cylinder, eithermanually or otherwise. The piston carries an upwardly extending pistonrod 45 which is supported by an accumulator bearing bracket 46 arrangedon top of and secured to the flanges 42 and 43 of the air cylinder andjacket of the accumulator. The bearing bracket 46 is provided with astuffing box 41 above which is arranged an oil cylinder 48. The pistonrod 45 is extended upwardly and provides a plunger for the oil cylinder,and this rod or plunger is sealed by means of the packing 41. The oilcylinder 46 is provided with a head 49 for closing the upper endthereof. The pipes 31, connected to the housing cylinders 23 of eachmill, are connected together by means of a pipe 50. This pipe isprovided with a branch pipe 5|, which is extended to the oil cylinder 46of the accumulator and which is connected to the head 49 of the oilcylinder, whereby a fluid-tight oil system is provided. The diameter ofthe piston rod 45 is relatively smaller than the diameter of the-housingpiston 24 and p ne 31.

. its displacement, therefore, is very much greater per unit oflongitudinal movement than the displacement of the housing piston,whereby the pressure on the housing piston is made sensitivelyresponsive to the action of the pressure of the air in the accumulator.

In order to compensate for any leakage of the oil from the oil system,we provide an oil pump 52 which is connected by means of a pipe 53 tothe oil cylinder 48 and which takes its supply of oil from a suitablesource (not shown) through the pipe 54. Obviously, when the supply is tobe replenished, the pump is manually operated in well known manner andoil is forced under pressure into the oil System.

The air jacket 39 of the accumulator is provided preferably with a gauge55, and it is obvious that, since the pressure of the air over therelatively large piston 44 is less than the pressure of the oil over thesmaller plunger 45, the presaaoaoea sure within the oil system will bein definite relation to the pressure of the air inthe air system and theoil pressure may, therefore, be accurately gauged from the pressure ofthe air in the jacket of the accumulator. So as to prevent thepossibility of an overload in the jacket 39, a safety valve 56 isprovided which, in the present case, is set to release at a pressurehaving a definite relation to'the other valves to be hereinafterdescribed. A suitable drain 51 is connected to the bottom of the tankwhereby condensation may be removed.

The air storage tank l2 preferably has sufficient capacity for supplyingair not only to the single accumulator shown in Figs. 1-7, inclusive,but to aseries of accumulators, as illustrated diagrammatically in Fig.8 and as hereinafter stated. The air jacket 39 of each of the airaccumulators II is connected to the tank I2 by means of two pipes 60 and6|, joined together by means of a pressure regulating valve 62 which isdesigned to act also as a shut-off valve, as hereinafter described. Thepipe BI is provided with a branch by means of each of their pipes 5| toa mill, not

shown. Each of these accumulators is provided with an air supply pipe6|, a branch pipe 63, a pressure regulating and shut-off valve 62 and arelief valve 64 connected in the manner similar to that described abovein connection with the single accumulator. Furthermore, the pipe 19carrying air from the supply tank l2 to the diaphragm chambers of thetwo valves just mentioned is also provided for each accumulator. Inorder that the accumulators be operated in unison and that the valves beoperated in unison through the medium of the emergency release valve l3,we connect the pipes 19, coupling each pair of valves 62 and 64 with abranch pipe 86. Likewise, the air supply pipes 6| from each accumulatorare connected to the supply pipe 60 coming from the air tankl2 by meansof a branch pipe 85.

The pressure regulating and shut-off valve 62 and the air relief valve64 are shown enlarged in Figs. 4 and 5, respectively. The pressureregulating and shut-off valve 62 comprises a diaphragm l0 forceddownwardly by means of a helical spring H, and a plug 12 which separatesthe pipes 60 and 6|. Attached to the housing and connected to the spaceunder the diaphragm 10 is an air supply pipe I3, to be hereinafterdescribed, and the plug of this valve is so arranged that it opens uponpressure exerted on the under-side of the diaphragm, whereby it willalso act as a shut-off valve under certain conditions, tobe hereinafterdescribed. The relief valve 64 comprises a diaphragm 15, a spring 16,and a plug 11. The plug ll of the relief valve is arranged in reversemanner to the plug 12 01 the pressure regulating and shut-off valve andis normally held upon its seat by the pressure of the spring I6 and bythe pressure of the air in the pipe 63. This valve is also provided withan air pipe 16 attached to the casing of the valve and positioned so asto exert pressure on the under side of the diaphragm 15. The air pipes13 and 16 are connected together by means of piping 19, which is in turnconnected to the air storage tank I2.

Arranged in the air piping I9 is the emergency release valve |3. Thisrelease valve is of the spring-pressed type and is normally closed. Thevalve is so designed, however. that by a single movement of the lever 80thereof, it may be unseated and allow air from the air storage tank I2to pass through the piping I9 and to the chambers below the diaphragms Iand I of the valves 62 and 64, respectively, to be hereinafterdescribed. The outlet pipe of the air relief valve 64 opens into theatmosphere and maybe connected to some suitable point outside of thebuilding by means of a pipe 8|.

When our device is to be put into use, air from the air storage tank I2will pass through pipes 60 and SI to the jacket 39 and cylinder 4| ofthe air accumulator. Such air, in passing to the accumulator, will passthrough the pressure regulating and shut-off valve 62 and the pressurewill be reduced to the amountdesired to be maintained in the airaccumulator. The parts of our device are so proportioned that, when theair has reached the desired pressure in the accumulator, the piston 44thereof will have moved upwardly which, together with a correspondingmovement of the-plunger 45, will, through the oil in the oil system,place the upper roll under proper pressure. Obviously, the pressureofthe, air in the tank I2 and the capacity thereof is made ample to supplythe number of accumulators used and to replenish any leakage of air fromthe accumulators without frequent operation of the air compressor (notshown) supplying air to the air storage tank. For practical purposes, wemay designate two hundred pounds as the pressure which is preferable tomaintain within the tank I2 and one hundred and fifty pounds as apressure desirable for the jacket 39 of the air accumulator. The air inthe accumulator is maintained at this definite pressure by means of theregulating valve 62, and the proper normal working pressure within thehousing cylinders 23 is thereby maintained. It will be obvious thatwhen. our device is operating under normal working'conditions, the airrelief valve 64 will be maintained in its closed position.

When sugar cane is now passed between the rolls I5 and I6 of the mill,the upper roll will be separated from the lower roll and the oil orfluid contained in the bearing block cylinders 23 will be forced outthrough the pipes 31 and through the pipes 50 and 5| to the oil cylinder48. The

flow of oil into the cylinder 48 causes movement of the piston rod orplunger 45, which movement is transferred to the air piston 44. Suchmovement isresisted by the pressure of the air contained in the jacket39 and cylinder 4| of the air accumulator, thereby maintaining thedesired pressure between the rolls of the mill. Due to the largevolumetric capacity of the jacket of the.

accumulator, the pressure of the air therein will be varied but slightlyunder the normal operating range of the device. Any leakage in the airsystem will immediately be replenished by air from the air storagetank,- thus maintaining the desired, predetermined pressure within'theair ac.-

highly desirable that the,pressure between the rolls be promptlyreleased. This can-be done with our device because of the provisionofthe emergency release valve I3 which, as hereinbefore stated, isconnected either to the single unit shown or to a battery of units. Thisemergency release valve may be placed in any suitable position andpreferably at such place where the operator can see the action of therolls of all the mills. When it is necessary to release pressure on therolls of the mills, the emergency release valve I3 is actuated whichallows air,

'under storage tank pressure, to, pass through the piping I9 to theinteriorof the casings of the pressure regulating and shut-ofi valve 62and air relief valve 64. Such air, coming into the easings of thesevalves will, through the pipes I3 and 18, be brought to bear against theunder side of each of the diaphragms I0 and I5, causing the plugs I2 and11, respectively, to be actuated. In the case of the pressure regulatingand shutoff valve 62, such actuation will cause the plug I2 thereof toclose, thus shutting oif further supply of the air from the tank throughthe pipe 60. In the case of the air relief valve 64, upward movement ofthe diaphragm will cause the plug 11 thereof to be opened. -When theplug I2 of the pressure regulating valve 62 is closed, and

foreign matter to pass therebetween without injury to the rolls or otherparts of the mill.

Obviously, some modifications of the details herein shown and describedmay be'made without departing from the spirit of our invention or thescope of the appended claims, and we do not, therefore, wish to belimited to the exact embodiment herein shown and described, the formshown being merely a preferred embodiment thereof.

Having thus described our invention, what we claim is:

1. In a sugar cane mill having stationary and movable bearing blocks,the combination with the movable bearing blocks thereof, of anindependent, stationarily-arranged housing cylinder for each block, amovable piston in each housing cylinder cooperating with said block, andan independent hydraulic accumulator, said accumulator comprising twostationary cylinders, a piston for each of said accumulator cylinders,said accumulator pistons being coactively engaged when producingpressure, said accumulator cylinders having bores of difierentdiameters, the smaller accumulator cylinder being connected to thehousing cylinder in a closed oil system, the larger accumulator cylinderbeing connected in a separate, closed air system and having its pistonacted upon by the pressure of the air in theair system, whereby theapplication of. air pressure of predetermined amount on the largercylinder will produce an application of greater pressure to the millbearing blocks by means of the piston in the smaller cylinder, an airpipe connecting a suitable source of air supply with the air cylinder ofthe accumulator, a pneumaticallyoperated shut-off valve in said pipe, abranch pipe connected .in said air pipe and having one end" thereof opento the atmosphere, a pneumaticallyoperated air relief valve connected insaid branch pipe, and emergency means connected in said air dependenthydraulic accumulator, said accumulator comprising two stationarycylinders, a piston for each of said accumulator cylinders, saidaccumulator pistons being coactively engaged when producing pressure,said accumulator cylinders having bores of diiferent diameters, the

smaller accumulator cylinder being connected to the housing cylinders ina closed oil system, the larger accumulator cylinder being connected inaseparate, closed air system and having its piston acted upon by thepressure of the air in the air system, whereby the application of airpressure of predetermined amount on the larger cylinder will produce anapplication of greater pressure to the mill bearing blocks by means ofthe piston in the smaller cylinder, an air pipe connecting a suitablesource of air supply with the air cylinder of the accumulator, apneumatically-operated shut-off valve in said pipe, a branch pipeconnected in said air pipe and having one end thereof open'to theatmosphere, a pneumatically-operated air relief valve in said branchpipe, each valve having a diaphragm chamber, an air pipe line connectingsaid source of air supply with the diaphragm chambers of said shut-ofivalve and said relief valve, and a. manually-actuated emergency reliefvalve con-- nected in said air pipe line for controlling the supply ofair to the diaphragm chambers of the shut-ofi and relief valves, wherebythe supply of air from the air storage tank is shut off and pressureupon the pistons of the housing cylinders is instantly removed byrelease of pressure within said air system through said relief valve.

3. In a sugar cane mill, the combination with an air supply tank, of ahydraulic accumulator, comprising two stationary cylinders, a piston foreach of said accumulator cylinders, said accumulator pistons beingcoactively engaged when producing pressure, one of said accumulatorcylinders being connected to the housing cylinders in,

a closed oil system, the other of said accumulator cylinders beingconnected in a separate, closed air system, an air pipe connecting saidair tank with the air cylinder of said accumulator, a shutoff valve insaid pipe, a branch pipe connected in said air pipe and having one endthereof open to the atmosphere, an air relief valve connected in saidbranch pipe, said supply tank having greater pressure and volumetriccapacity than that of the air cylinder of the accumulator forimmediately replenishing air losses from the air cylinder of theaccumulator, and manual means mechanically interconnected forsimultaneously closing said shut-off valve and opening said reliefvalve, whereby pressure upon the pistons of the housing cylinders may beinstantly removed by release of pressure within said air system.

4. In a sugar cane mill having stationary and movable bearing blocks,the combination with the movable bearing blocks thereof of anindependent, stationarily-arranged housing cylinder for each block, amovable piston in each housing cylinder cooperating with said block, an.air supply tank, an independent hydraulic accumulator, said accumulatorcomprising two stationary cylinders, a piston for each of saidaccumulator cylinders, said accumulator pistons being coactively engagedwhen producing pressure, said accumulator cylinders having bores ofdifferent diameters, the smaller accumulator cylinder being connected tothe housing cylinders in a closed oil system, the larger accumulatorcylinder being connected in a separate, closed air system and having itspiston acted upon by the pressure of the air in the air system, wherebythe application of air pressure of predetermined amount in the largeraccumulator cylinder will produce an application of greater pressure tothe mill bearing blocks by means of the piston in the smaller cylinder,an air supply pipe connecting said air tank with the air cylinder ofsaid accumulator, a pneumatically-operated shut-off valve in said supplypipe, a branch pipe connected in said air supply pipe and having one endthereof open to the atmosphere, a pneumatically-operated air reliefvalve connected in said branch pipe, each valve having a diaphragmchamber, an air line connecting the air supply tank with the diaphragmchamber of said shut-off valve and said relief valve, said supply tankhaving a greater pressure and volumetric capacity than that of the aircylinder of said accumulator for immediately replenishing air lossesfrom the air cylinder of said accumulator, and manually-actuatedemergency means connected in said air line to control the closing ofsaid shut-off valve and the opening of said relief valve, wherebypressure upon the pistons of the housing cylinders may be instantlyremoved by release of pressure within said air system.

EUGENE A. SCHWARZ. OTTO FABER.

